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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Link to relevant study record(s)

Description of key information

The following information is available for this endpoint:
Graves, W. C. and Swigert, J. P (1997). Hexabromocyclododecane (HBCD): 48-hour flow-through acute toxicity test with the Cladoceran (Daphnia magna). Report no.: 439A-102. Report date: 1997-05-21.
Priestly, S. L. (2008a). EPS - Styropor F 215-N, Lot 39-2704: Acute toxicity to Daphnia magna. Report no.: 2631/0001.Report date: 2008-10-27.
Priestly, S. L. (2008b). XPS - Styrodur 2800C 40mm, Lot 286 985 75LO: Acute Toxicity to Daphnia magna. Report no.: 2631/0003. Report date: 2008-10-27.
Graves and Swigert (1997) was selected as the key study as it was considered to be the most reliable and relevant study available.

Key value for chemical safety assessment

Additional information

The commercial HBCDD product was not acutely toxic to Daphnia magna. HBCDD’s 48 hour EC50, no mortality/immobility concentration, and NOEC (6.8 µg/L nominal) in Daphnia magna were all greater than gamma HBCDD’s water solubility (3.4 µg/L measured). The highest nominal dose tested was twice gamma HBCDD’s water solubility. Nominal test concentrations were 0, 1.5, 2.2, 3.2, 4.6 and 6.8 µg/L which corresponded to mean measured concentrations (HPLC with UV/VIS detector) of 0, 2.4, 1.8, 2.1, 2.3 and 3.2 µg/L, respectively (Graves and Swigert, 1997). A composite of three manufacturers' commercial products was used as test article in the above study. The dose levels in the study were based on the water solubility of HBCDD (approxiamtely 3.4 µg/L) determined via quantiation on the gamma diastereomer. The alpha and beta diastereomers were not quantifiable at a gamma concentration of 3.4 µg/L due to their low concentrations in the test article. Correcting for gamma diasteromer content in the test article, the 48 hour NOEC was > 8.5 µg/L of the commercial product in water.

The lack of acute toxicity in daphnia was also observed in the Daphnia 21 day study, using the commercial HBCDD product as test article. No mortality was observed at 48 hour at nominal concentrations up to 13.6 µg/L (11 µg/L, measured, based on gamma diasteromer). Correcting for the content of the gamma diastereomer, the nominal concentration was 17.2 µg/L. Thus, the 48 hour EC50 in daphnia of the HBCDD commercial product is > 17.2 ug/L.

The HBCDD commercial product has not been tested in Daphnia at higher doses.

The 48 hour effective loading rate 50 (EL50) of XPS or EPS foam boards flame retarded with HBCDD was > 100 mg board/L.

Thus, HBCDD was not acutely toxic to daphnia when tested up to and five times the limit of solubility of the gamma diastereomer, or when the commercial product was incorporated into XPS or EPS foam